Shortly after a British Airways Airbus A319 left Edinburgh for London Heathrow, its autopilot and autothrust disconnected. The aircraft then lost positional information from its combined satellite-and-inertial navigation system. The disturbance had begun before it became airborne, with vertical shocks transmitted through the nose landing gear during the takeoff roll.
The flight, operated by A319-131 G-EUPS on October 30, 2025, continued to Heathrow using radar vectors. The crew declared a PAN urgency call and managed to re-engage the autopilot and autothrust. Both disconnected again during the approach. A further fault involving the rudder travel limiter immediately before landing prompted a go-around, after which the aircraft landed safely.
The Air Accidents Investigation Branch published its findings on October 8, 2026. The occurrence has returned to attention through new safety coverage this week.
Investigators traced the system faults to severe 'drift' in the aircraft’s inertial-reference system. Such a system uses sensors to track the aircraft’s motion and orientation, providing information used by navigation and other aircraft systems. If those measurements become unreliable, the consequences can extend beyond the position shown on a map.
That was the pattern aboard G-EUPS. The AAIB linked the autopilot and autothrust disconnections, loss of positional information and rudder-limiter fault to the inertial-reference disturbance. The problem affected several functions because they depended on the same underlying information.
The initiating force was mechanical. During takeoff, shocks passed from the nose landing gear into the aircraft and its air-data inertial-reference units. The cockpit voice recorder captured two larger sound impulses from the nose gear. Investigators did not establish the exact source of the shock loading, and examinations found no damage or irregularity in either the nose landing gear or the reference units.
A shock absorber cushions the airframe from runway loads; it does not isolate it completely. In this case, the resulting disturbance upset the reference system without leaving a damaged component that investigators could identify afterwards. Airbus already knew that the units could be sensitive to shock loads outside their certification requirements.
Edinburgh had experienced a similar occurrence four years earlier. On August 6, 2021, another British Airways A319, G-DBCF, suffered inertial-reference drift after departure. Investigators identified a slightly uneven runway repair and a nose-gear shock absorber that was overextended by 15 millimetres, reducing its ability to cushion the impact. The jolt travelled into the airframe and the avionics rack housing the reference units.
That earlier crew also lost autopilot and autothrust operation during the flight, restored them, and then experienced another disconnection on approach to Heathrow. They discontinued the approach, briefed for a manually flown landing and landed without further incident. Edinburgh subsequently replaced the uneven repair patch.
The findings from the two flights are not identical. The earlier investigation identified both a suspect repair patch and a shock-absorber servicing discrepancy. In the 2025 occurrence, the AAIB found no nose-gear irregularity and could not determine the exact source of the shocks.
Edinburgh has since fully resurfaced its runway. The investigation concluded that the work would minimise the probability of surface irregularities affecting other aircraft.
G-EUPS, the disruption lasted beyond the moment the wheels left the ground. A brief physical load during takeoff had unsettled information used throughout the flight, leaving the crew to manage repeated system disconnections, accept radar guidance and complete a second approach at Heathrow.